The reason the Samsung SOC has slightly less battery life than TSMC is because the Samsung can run at a higher clock speed for sustained periods without throttling. This is due to the smaller 14nm size. So battery tests that strain the CPU will result in more consistent performance but higher battery drain since there's less throttling. So it depends what you really want from your phone. I don't live in a jungle so can charge my phone when needed and I'd rather have consistent performance and less throttling with a small impact on battery life. Remember when the SOC throttles it uses less battery. We went through this a few years ago on Android with Snapdragon and Samsung SOCs as they improved the process.